testing ECU to make sure it works?? now with WRITE UP :) and pics...
 

so i was watching my roommate assemble a MegaSquirt and got an idea...i need to make a 'simulator' (what the megasquirt guys call it) to test a ECU to make sure that they are working...

so here is my plan, and i need a little help.....oh yeah im talking about OBD1 Honda ECU;s (but im sure the idea would work with others too)... basicly i just want to make sure that the ECU turns on and isnt a solid CEL... so im guessing that i would just need a power (household 9v battery?), ground, CEL signal with an LED inline to the ground....that it?
i realize that when i plug this in it will throw a shitload of CEL's but thats the idea, if the LED blinks its a good ECU ;)

so am i on the right track here? will this work?

Re: testing ECU to make sure it works??
 

Just use a 12v battery.

Re: testing ECU to make sure it works??
 

well a 12v battery sitting in the living room doesnt make my roommates happy, somethign about non-sealed batteries and battery acid :-\

9v should be good enough to power up the ECU...

Re: testing ECU to make sure it works??
 

You can buy a 12v adapter from RadioShack.

Clip a harness from a junk yard car that will plug into your ECU, then you have the daunting task of emulating sensors.

Some of them can be hacked with various 5v potentiometers, however, OBD1 is very finiky about it's EACV. YOu might just actually have to hook that one up. When simulating an OBD0 ECU you can just splice a 10w10o resistor.. but that doesn't fool OBD1.

Anyway.. you should be able to simulate enough to get rid of the CELs with some afro-engineering.

Let me know if you need specifics that you can't figure out... I used to do this with OBD0 so I could test dataloggier for TE on my desktop inside my nice warm office. ;)

Re: testing ECU to make sure it works??
 

I was assuming that this would be somewhere other than the living room.

Re: testing ECU to make sure it works??
 

fine i can use a car battery, i jsut didnt want to go to the garage.... but not the point right now....

i need some help figuring out what wires i should be connecting where... ???

Re: testing ECU to make sure it works??
 

lol. Yeah the diehard on the coffee table is a good look.

Re: testing ECU to make sure it works??
 

On OBD0 ECUs I use the Radio Shack 12v power supply that i found for like $40.

Put power to A13 and ground to A16 and it will start up the ECU.

Throws code 6, 10 and 13 but at least you know your soldering and chip are good.

OBD1 I havent attempted to figure out yet...but like Parker says, get a junkyard harness and hook it up

screw the 12v battery...:)

Re: testing ECU to make sure it works??
 

thanks...thoughts are formulating...i still have my OBD0 to OBD1 jumper.... want to make a OBD0 tester also......

Re: testing ECU to make sure it works??
 

k, made a OBD0 test harness...------ easy (take pics later ;) ) 9v battery works fine... tested it on a PS9, solid CEL :-\

anyway i looked at my OBD0-1 jumper, got the wires i need.... but how does the CEL work on this? i have a little LED, but im not getting how i should be hooking this up in there?????

Re: testing ECU to make sure it works??
 

i've got one i made that i'm gonna test tomorrow, i'll post it up once/if i get it working.

Re: testing ECU to make sure it works??
 

that would be sweet.

Re: testing ECU to make sure it works??
 

k, think i got it...but the LED im using isnt working like i would like it (maybe the wrong kind?). the light will light up, and you can see a faint blinking....codes 10 and 6.... IAT and ECT codes, so it works perfect.... also means i didnt ---- that P06 up 8)

Re: testing ECU to make sure it works??
 

you using a 12v led?

Re: testing ECU to make sure it works??
 

im not sure what the ---- it is accually ::) it came from my Megasquirt kit (there is a min order, you get 5 more than you need).... i think i will head to the radio shack today and get a standard 12v LED and some power connectors then take pics of what i have come up with... :-*

Re: testing ECU to make sure it works??
 

please do :)

Re: testing ECU to make sure it works??
 

ECU Test Harness Write Up for OBD0 & OBD1 (my experinces...dont come to me whining if it doesnt work or fucks up your ECU...)


OBD0 test harness:
http://home.comcast.net/~turbohf/harness0.jpg
solid CEL.... :-\

pins: A13 power, A16 ground... got the little 9v plug at Radio Shack...9v battery stolen from my roommates desk (thanks Aaron ;))


OBD1 test harness:
http://home.comcast.net/~turbohf/harness1.jpg
codes: 6 and 10 <~means it works

pins: A25 power, B2 ground... one side of LED to power the other to A13, D4 to ground... LED is extra ---- from my Megasquirt (not the best choice for LED for this btw), and the power adapter well they come in packs of 5 at RS... 9v battery stolen from my roommates desk (thanks Aaron ;))

Re: testing ECU to make sure it works?? now with WRITE UP :) and pics...
 

Noice! ;)

Re: testing ECU to make sure it works?? now with WRITE UP :) and pics...
 

awesom job! how did you figure out to ground d4? that's the only thing i wasn't doing right, just wondering how you figured that out. also, you told me the led was barely lighting? maybe b/c you only have a 9v power supply? how you tried with any type of 12v power to see if that makes a difference? good job man, now i can finally permanently mount my own ecu in my car instead of having to leave my kick panel off and ecu on the floor just so i can test ecu's every night :D next project, get a complete obd1 harness that simulates all sensors so you will even know if you're getting cel code 8)

Re: testing ECU to make sure it works?? now with WRITE UP :) and pics...
 

D4 is part of the "blink the check engien light for codes", instead of using the two pin service connector over on the passenger side kick panel.

This is an old school OBD0-OBD1 conversion trick, for those who didn't have a "service connector" to jump. :D

Re: testing ECU to make sure it works?? now with WRITE UP :) and pics...
 

werd :)

Re: testing ECU to make sure it works?? now with WRITE UP :) and pics...
 

yeah i grounded the D4 cuz im a OBD0-1 swapper like TurboEF9 said....


the problem with the LED is that i have no idea WTF it is.... the light isnt dim, its on all the time...its the blinking that is faint. i tried a 12v light from RS but it just seemed to want to stay on all the time?


this is awsome! i dont even have a running car to test ---- in (selling the car)....umm guess i still ginnie pig to make sure VTEC works right...

Re: testing ECU to make sure it works?? now with WRITE UP :) and pics...
 

i bet you wouldn't get a solid cel if you used a 12 volt source ::)

Re: testing ECU to make sure it works?? now with WRITE UP :) and pics...
 

wtf? that ECU is fucked up... it has nothing to do with the fact that im using a 9v battery, if anything it would just be a weaker light...

Re: testing ECU to make sure it works?? now with WRITE UP :) and pics...
 

Just what I was working on. I want to make a stim just like my megasquirt has as well. It really shouldn't be that hard. Just need to find some time to actually do it.

Very nice though.

Re: testing ECU to make sure it works?? now with WRITE UP :) and pics...
 

Back from the dead yo'

Followed Dustins instructions. Works great.

http://[IMG]http://img160.imageshack....jpg[/img]

Mine does the same thing were the LED stays on, and you have to look closely to count the blinks. ---- works though.

Re: testing ECU to make sure it works?? now with WRITE UP :) and pics...
 

wow, ---- looks nice! must be a bitch to remove though... oh i cut the little tabs off mine so the plugs slide off easier...

Re: testing ECU to make sure it works?? now with WRITE UP :) and pics...
 

So the point is to verify you don't have a solid CEL?

Re: testing ECU to make sure it works?? now with WRITE UP :) and pics...
 

Easy to get out, I always just use my keys to unplug ECU's. I pulled the LED from a junk OBD0 ecu; I noticed that it had a 22k resistor on it, so I stacked 2 10k resistors inside the shrink wrap. Also of note, the LED can only be hooked up one way, so you need to test for polarity before you solder. I didnt, and had to redo it :1

Re: testing ECU to make sure it works?? now with WRITE UP :) and pics...
 

Yeah. I dont have my CRX at my house right now, and needed a way to test ECU's that I'm chipping.

Re: testing ECU to make sure it works?? now with WRITE UP :) and pics...
 

well if your chip shitloads of ECU;s and or dont have a car to test them in (like me at the time of this thread) this is a great plan....

Dave no pics of the OBD0 harness? ::)

Re: testing ECU to make sure it works?? now with WRITE UP :) and pics...
 

I dont have one. I havnt chipped on OBD0 since I completely destroyed 2 of Jeff's ECU's :6

Re: testing ECU to make sure it works?? now with WRITE UP :) and pics...
 

No, I'm serious. I don't have an OBD1 car avail. at all times to test ECU's I chip, and it sucks waiting around. Build one of these, and as long as I get some codes I'm golden is how I'm seeing it right now, but it's late and I wanted to make sure. :)

Re: testing ECU to make sure it works?? now with WRITE UP :) and pics...
 

yeah i guess i read that wrong...

Re: testing ECU to make sure it works?? now with WRITE UP :) and pics...
 

Cool, I've even got some harnesses lying around. Pimpshizzle.

Re: testing ECU to make sure it works?? now with WRITE UP :) and pics...
 

DAMN, and I thought I was the only one who did that.

Everyone I meet says that they hate getting out OBD1 plugs. I tell em, "use your honda key, push the release and pry from the bottom"

Re: testing ECU to make sure it works?? now with WRITE UP :) and pics...
 

ya pullin out those stock eproms always makes me nervous. I trashed a pr4 a couple months back

Re: testing ECU to make sure it works?? now with WRITE UP :) and pics...
 

Nice work guys.I never seen this thread for some reason.Im chipping a ecu tommorow and will try this out :6

Re: testing ECU to make sure it works?? now with WRITE UP :) and pics...
 

Very nice work and easy to read and understand. Should be stickied or in the tech project section!

Re: testing ECU to make sure it works?? now with WRITE UP :) and pics...
 

awsome idea, i always hate to take off my kick panel just to test and see if it works when i get done.